Five Lehigh Valley businesses that have financial interests in South Africa were visited by a committee of seven local activists yesterday afternoon and urged to "disinvest" because of that nation's apartheid policies.

Receiving the Anti-Apartheid Committee of the Lehigh Valley were the Hamilton Mall investment firms of E. F. Hutton & Co. and Prudential-Bache Securities, Allentown; Goodyear and IBM in the Whitehall Mall area, and Air Products and Chemicals, Trexlertown. At each stop the committee left literature stressing the degradation and suffering of South Africa's blacks even though they make up 85 percent of the country's 24-million people.

Co-chairmen Donald W. Miles and Jane Gaughran conceded that most of the business people they spoke with yesterday work on subordinate levels and have nothing to do with company policy-making. But they requested that literature be passed on to the respective headquarters where officials do make decisions relating to humanitarian considerations.

Among those joining the co-chairmen were the Rev. Bill Watson of Easton, a member of the Committee on Church and Society of the Allentown Division, United Methodist Church; the Rev. Frank Sanders, pastor of Trinity United Methodist Church, Allentown, and Amy Ongiri, a native of Minnesota whose father was born and reared in Kenya, West Africa.

One of the aims of yesterday's activity was to focus attention on the "National Day of Protest Against Apartheid" to be observed this Friday in combination with "South Africa Political Prisoner Day" across the nation. There will be a vigil at noon at Center Square, Allentown, with participants being asked to wear black arm bands.

But the committee will swing into action at 7:30 p.m. tomorrow with a program at Grace Deliverance Baptist Church, 838 N. New St., Bethlehem. A South African student from the embattled area of Soweto will tell what it is like "Living Under Apartheid," and a Presbyterian minister will talk on "To Divest: Why and How." It will be sponsored by the anti-apartheid committee and the Lehigh-Pocono Committee of Concern (Lepoco).

In an unrelated statement yesterday, Richard P. Burton, president of the Allentown chapter of the NAACP, reported on advice given chapter officials recently by Benjamin Hooks, national head of the organization. Hooks asked that all local anti-apartheid demonstrations be meaningful and constructive.

Said Burton, "These demonstrations may be as creative as one would like. However, under no circumstances are demonstrations to be unlawful. That is to say, we do not expect, or encourage, anyone to get arrested . . . We would not want to hurt the cause of our organization through violence."

He added, "Care should be taken to secure the appropriate permits. We would like to see as many community organizations, which have the same positions on this issue as does the NAACP, work toward ending apartheid."

Although some of the business representatives appeared to be surprised yesterday by the committee's visit, they listened attentively to the argument that doing business in South Africa, and employing some educated blacks, is doing nothing to alleviate poverty and government repression.

At the Allentown office of Prudential-Bache, whose international organization reportedly has $443 million invested in South Africa's white- dominated economy, manager Robert Turner invited the group into his office and said that he would pass the literature on to his superiors. When asked by a reporter if management had issued any recent statement on its dealings with South Africa, Turner replied, "I haven't heard a thing."

On a visit to the nearby office of E.F. Hutton, Jack R. Simpson Jr., assistant manager, was asked to relay the committee's literature to Hutton's officials in New York. Simpson replied, "They'll get it."

Near the end of the three-hour tour, attorney Miles noted that Air Products was the only company that had a locally based headquarters where policy was, indeed, made. When Miles drove up to the main gate at Trexlertown and said he wanted to visit the president's office, a polite security guard said that his contingent, now down to a few, "are expected."

As it turned out, Air Products was the only company among those visited that supplied the committee with a two-page "background" statement on South Africa, where it has only part-interest in an industrial gas company.

Greeting Miles and Gaughran was William J. Roberts, director of public relations and marketing communications.